This invention relates to the packaging of at least two mutually reactive particulate materials and in particular two or more reactive materials for use in the development of exposed photographic films.
The development of exposed photographic films comprises the step of successively passing said films through developer and fixing baths consisting of aqueous solutions of substances which are solid at room temperature. During use, the efficiency of such baths gradually decreases and, therefore, fresh baths have to be prepared at certain intervals.
Some of the solid materials which are used for the preparation of such developer and fixing baths tend to react with one another to form undesired reaction products if they are brought into direct contact with one another. Therefore, they cannot be shipped to the user in the form of a mixture. Up to now it has been necessary to pack these substances or groups of substances in separate packages and to effect the mixing shortly before or in connection with the preparation of said baths. This has resulted in relative high packaging and transportation costs and has also caused problems for the user who is to prepare said baths. Thus, the user has to take extra care that the correct materials are used in the correct proportions.
It has been attempted to avoid these problems by preparing concentrates of the desired solutions and to send these concentrates to the users, who then have to dilute the concentrates to make them suitable for use. This solution presents the serious disadvantage that a substantial amount of water has to be transported from the manufacturer to the user and that such concentrates cannot be sent as airfreight because the airline companies normally are unwilling to transport solutions of chemical compounds.
A further problem involved in the transportation of concentrates is that a precipitate which may be difficult to re-dissolve can be formed if the concentrate is cooled during such transport.
The object of the invention is to eliminate the problems discussed above.